Yokose virus

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Yokose virus
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Kitrinoviricota
Class: Flasuviricetes
Order: Amarillovirales
Family: Flaviviridae
Genus: Flavivirus
Species:
Yokose virus
Synonyms. [1]

Yokase virus

Yokose virus (YOKV) is in the genus Flavivirus of the family Flaviviridae. [2] Flaviviridae are often found in arthropods, such as mosquitoes and ticks, and may also infect humans. The genus Flavivirus includes over 50 known viruses, including Yellow Fever, West Nile Virus, Zika Virus, and Japanese Encephalitis. Yokose virus is a new member of the Flavivirus family that has only been identified in a few bat species. Bats have been associated with several emerging zoonotic diseases such as Ebola and SARS. [3]

Contents

Viral classification

A picture of Mount Also, located on Kyushu Island Japan, where Yokose virus was first isolated. Mount Aso, Kyushu Island, Japan.jpg
A picture of Mount Also, located on Kyushu Island Japan, where Yokose virus was first isolated.

Yokose virus belongs to the genus Flavivirus of the family Flaviviridae. It was identified in 1971 in Oita prefecture, Kyushu Island, Japan. The strain Oita-36 was isolated from bat species Miniopterus fuliginosus . [4] Molecular genetic analysis has shown that Yokose virus is a new member of the Flavivirus genus. [4] Flaviviruses are typically divided into three groups: mosquito borne, tick borne, or non-vector. Yokose virus is classified as NKV, or no-known vector. This means that it has no known arthropod vector. However, there is some evidence suggests that it may infect arthropods, namely being mediated by mosquitos. Yokose virus has been found to be genetically close to Yellow Fever virus with amino acid sequences showing close identify to Entebbe Bat virus. [4]

Viral structure and genome

Yokose virus is a positive sense single-stranded RNA virus. It is enveloped and has icosohedral symmetry with a triangulation number (T) of 3. [5] It is roughly 50 nm in diameter. The genome is non-segmented and contains 10,857 nucleotides. [4] There is one open reading frame (ORF) of 3425 amino acid polyprotein that encodes three structural proteins and eight non-structural proteins. [4] The structural proteins include capsid (C), premembrane/membrane (prM), and envelope (E). The non-structural proteins include NS1, NS2A, NS2B, NS3, NS4A, 2K, NS4B, and NS5. Protein 2K is not found in many other flaviviruses. NS3 functions as a protease and helicase. NS5 functions as the RNA-dependent RNA polymerase. NS1 is important in the viral replication process. NS2A interacts with NS3 and NS5, helps in viral assembly and recruits the viral RNA genome to membrane-bound replication complex. Secondary structures formed by 5' and 3' of non-translating region (NTR) influence transcription and translation. Yokose virus has a CS1 motif in the 3' NTR which is conserved in mosquito-borne flaviviruses suggesting ability to infect arthropods. [4]

Replication cycle

Entry into cell

The viral envelope protein (E) attaches to the host cell receptors and is taken into the cell via endocytosis. The envelope protein then undergoes a conformational change within the endosome upon exposure to the endosome's acidic nature. [5] The envelope protein and the endosomal membrane fuse, and the virus is released into the cytoplasm.[ citation needed ]

Replication and transcription

The viral RNA is translated into a polyprotein and then cleaved by viral and cellular proteases into the structural (C, prM, and E) and non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, 2K, NS4B, and NS5). [6] Replication takes places on the surface of the endoplasmic reticulum within the membrane vessicles. A complementary negative sense RNA strand is formed via the RNA-dependent RNA polymerase (non-structural protein NS5) to create a double-stranded RNA. [6] The dsRNA is transcribed producing viral mRNAs.[ citation needed ]

Assembly and release

The virus is assembled within the endoplasmic reticulum. A nucleocapsid is formed and takes up viral glycoproteins. However, very little is understood about the assembly process of Flaviviruses. Evidence suggests that several of the non-structural proteins such as NS2A contributes to assembly. [6] The assembled vision then buds to the Golgi apparatus where the prM protein is cleaved leading to maturation. [5] The virus is then released from the cell via exocytosis and is off to infect other host cells.[ citation needed ]

A fruit bat from the area where Yokose virus antibodies have been found in fruit bats. Lesser short-nosed fruit bat (Cynopterus brachyotis).jpg
A fruit bat from the area where Yokose virus antibodies have been found in fruit bats.

Host and location

Much is unknown about the pathogenicity and virulence of Yokose virus including in bats. The strain XYBX1332 isolated in China was found to cause cytopathic effects in mammalian cells. [7] In the study of fruit bats infected with Yokose virus, they did not observe any clinical signs of disease. [8]

Currently only species of bats have been identified of carrying Yokose viral strains. The strain Oita-36 was isolated from bat species Miniopterus fuliginosus and is currently the primary strain of Yokose virus. It was identified on Kyushu Island off the coast of Japan. Yokose virus is not geographically limited to Japanese islands, but has been isolated in inland China as well. Strain XYBX1332 was isolated from bat species Myotis daubentonii in Yunnan Province, China. [7] However, this strain has genomic differences compared to the original Oita-36 strain and further research should be conducted to conclude if it is a new species of flavivirus. Antibodies to Yokose virus were found in fruit bats, Rousettus leschenaultii , in the Philippines and Malaysia as well. [8] This shows that Yokose virus is not geographically limited to Japanese islands, but can exist in inland areas of Asia as well.

So far there has been no reported infections of Yokose virus in humans or other animals. Researchers found that Yokose can be manipulated to infect human cells and reacts to antibodies of other Flavivirus present within the cells. It was found that Yellow fever vaccination was effective in neutralizing Yokose virus in human cells. [4]

Pathogenicity and virulence

Much is unknown about the pathogenicity and virulence of Yokose virus. The strain XYBX1332 isolated in China was found to cause cytopathic effects in mammalian cells. [7] In the study of fruit bats infected with Yokose virus, they did not observe any clinical signs of disease. [8] However, a study conducted on bat alveolar epithelial cells and kidney cells found that infection of Yokose virus led to viral replication and cell death shortly after. [3]

Related Research Articles

<i>Flaviviridae</i> Family of viruses

Flaviviridae is a family of enveloped positive-strand RNA viruses which mainly infect mammals and birds. They are primarily spread through arthropod vectors. The family gets its name from the yellow fever virus; flavus is Latin for "yellow", and yellow fever in turn was named because of its propensity to cause jaundice in victims. There are 89 species in the family divided among four genera. Diseases associated with the group include: hepatitis (hepaciviruses), hemorrhagic syndromes, fatal mucosal disease (pestiviruses), hemorrhagic fever, encephalitis, and the birth defect microcephaly (flaviviruses).

<i>Hepadnaviridae</i> Family of viruses

Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently 18 species in this family, divided among 5 genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hepatitis, hepatocellular carcinomas, and cirrhosis. It is the sole accepted family in the order Blubervirales.

<i>Flavivirus</i> Genus of viruses

Flavivirus, renamed Orthoflavivirus in 2023, is a genus of positive-strand RNA viruses in the family Flaviviridae. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika virus and several other viruses which may cause encephalitis, as well as insect-specific flaviviruses (ISFs) such as cell fusing agent virus (CFAV), Palm Creek virus (PCV), and Parramatta River virus (PaRV). While dual-host flaviviruses can infect vertebrates as well as arthropods, insect-specific flaviviruses are restricted to their competent arthropods. The means by which flaviviruses establish persistent infection in their competent vectors and cause disease in humans depends upon several virus-host interactions, including the intricate interplay between flavivirus-encoded immune antagonists and the host antiviral innate immune effector molecules.

<i>Dengue virus</i> Species of virus

Dengue virus (DENV) is the cause of dengue fever. It is a mosquito-borne, single positive-stranded RNA virus of the family Flaviviridae; genus Flavivirus. Four serotypes of the virus have been found, and a reported fifth has yet to be confirmed, all of which can cause the full spectrum of disease. Nevertheless, scientists' understanding of dengue virus may be simplistic as, rather than distinct antigenic groups, a continuum appears to exist. This same study identified 47 strains of dengue virus. Additionally, coinfection with and lack of rapid tests for Zika virus and chikungunya complicate matters in real-world infections.

<i>Tick-borne encephalitis virus</i> Species of virus

Tick-borne encephalitis virus (TBEV) is a positive-strand RNA virus associated with tick-borne encephalitis in the genus Flavivirus.

<i>Alphavirus</i> Genus of viruses

Alphavirus is a genus of RNA viruses, the sole genus in the Togaviridae family. Alphaviruses belong to group IV of the Baltimore classification of viruses, with a positive-sense, single-stranded RNA genome. There are 32 alphaviruses, which infect various vertebrates such as humans, rodents, fish, birds, and larger mammals such as horses, as well as invertebrates. Alphaviruses that could infect both vertebrates and arthropods are referred dual-host alphaviruses, while insect-specific alphaviruses such as Eilat virus and Yada yada virus are restricted to their competent arthropod vector. Transmission between species and individuals occurs mainly via mosquitoes, making the alphaviruses a member of the collection of arboviruses – or arthropod-borne viruses. Alphavirus particles are enveloped, have a 70 nm diameter, tend to be spherical, and have a 40 nm isometric nucleocapsid.

<i>Orbivirus</i> Genus of viruses

Orbivirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Sedoreovirinae. Unlike other reoviruses, orbiviruses are arboviruses. They can infect and replicate within a wide range of arthropod and vertebrate hosts. Orbiviruses are named after their characteristic doughnut-shaped capsomers.

<i>Pestivirus</i> Genus of viruses

Pestivirus is a genus of viruses, in the family Flaviviridae. Viruses in the genus Pestivirus infect mammals, including members of the family Bovidae and the family Suidae. There are 11 species in this genus. Diseases associated with this genus include: hemorrhagic syndromes, abortion, and fatal mucosal disease.

<span class="mw-page-title-main">Viral disease</span> Human, animal or plant disease resulting from a viral infection

A viral disease occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells.

Entebbe bat virus is an infectious disease caused by a Flavivirus that is closely related to yellow fever.

Spondweni virus is an arbovirus, or arthropod-borne virus, which is a member of the family Flaviviridae and the genus Flavivirus. It is part of the Spondweni serogroup which consists of the Sponweni virus and the Zika virus (ZIKV). The Spondweni virus was first isolated in Nigeria in 1952, and ever since, SPONV transmission and activity have been reported throughout Africa. Its primary vector of transmission is the sylvatic mosquito Aedes circumluteolus, though it has been isolated from several different types of mosquito. Transmission of the virus into humans can lead to a viral infection known as Spondweni fever, with symptoms ranging from headache and nausea to myalgia and arthralgia. However, as SPONV is phylogenetically close to the ZIKV, it is commonly misdiagnosed as ZIKV along with other viral illnesses.

Royal Farm virus, previously known as Karshi virus, was not viewed as pathogenic or harmful to humans. Although infected people suffer with fever-like symptoms, some people in Uzbekistan have reported with severe disease such as encephalitis and other large outbreaks of fever illness connected infection with the virus.

<i>West Nile virus</i> Species of flavivirus causing West Nile fever

West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus. The virus is primarily transmitted by mosquitoes, mostly species of Culex. The primary hosts of WNV are birds, so that the virus remains within a "bird–mosquito–bird" transmission cycle. The virus is genetically related to the Japanese encephalitis family of viruses. Humans and horses both exhibit disease symptoms from the virus, and symptoms rarely occur in other animals.

Parramatta River virus (PaRV) is an insect virus belonging to Flaviviridae and endemic to Australia. It was discovered in 2015. The virus was identified from the mosquito Aedes vigilax collected from Sydney under the joint research project by scientists at the University of Queensland and the University of Sydney. In experimental infections, the virus is unable to grow in vertebrate cells, but only in Aedes-derived mosquito cell lines. This suggests that the virus does not infect vertebrates. The name is given because it was discovered from Silverwater, a suburb of Sydney on the southern bank of the Parramatta River. The mosquitoes from which the virus was isolated were actually collected in 2007, and had been preserved since then. The study commenced only after the development of the technique of viral detection in mosquitoes in the University of Queensland.

<span class="mw-page-title-main">Palm Creek virus</span> Species of virus

Palm Creek virus (PCV) is an insect virus belonging to the genus Flavivirus, of the family Flaviviridae. It was discovered in 2013 from the mosquito Coquillettidia xanthogaster. The female mosquitoes were originally collected in 2010 from Darwin, Katherine, Alice Springs, Alyangula, Groote Eylandt, Jabiru and the McArthur River Mine, and had since been preserved. The discovery was made by biologists at the University of Queensland. The virus is named after Palm Creek, near Darwin, from where it was originally isolated.

Jingmenvirus is a group of positive-sense single-stranded RNA viruses with segmented genomes. They are primarily associated with arthropods and are one of only two known segmented RNA viruses that infect animal hosts. The first group member, the Jingmen tick virus (JMTV), was described in 2014. Another member, the Guaico Culex virus (GCXV), has a highly unusual multicomponent architecture in which the genome segments are separately enclosed in different viral capsids.

<i>Sepik virus</i> Mosquito transmitted virus endemic to Papua New Guinea

Sepik virus (SEPV) is an arthropod-borne virus (arbovirus) of the genus Flavivirus and family Flaviviridae. Flaviviridae is one of the most well characterized viral families, as it contains many well-known viruses that cause diseases that have become very prevalent in the world, like Dengue virus. The genus Flavivirus is one of the largest viral genera and encompasses over 50 viral species, including tick and mosquito borne viruses like Yellow fever virus and West Nile virus. Sepik virus is much less well known and has not been as well-classified as other viruses because it has not been known of for very long. Sepik virus was first isolated in 1966 from the mosquito Mansoniaseptempunctata, and it derives its name from the Sepik River area in Papua New Guinea, where it was first found. The geographic range of Sepik virus is limited to Papua New Guinea, due to its isolation.

<i>Modoc virus</i> Species of virus

Modoc virus (MODV) is a rodent-associated flavivirus. Small and enveloped, MODV contains positive single-stranded RNA. Taxonomically, MODV is part of the Flavivirus genus and Flaviviridae family. The Flavivirus genus includes nearly 80 viruses, both vector-borne and no known vector (NKV) species. Known flavivirus vector-borne viruses include Dengue virus, Yellow Fever virus, tick-borne encephalitis virus, and West Nile virus.

<span class="mw-page-title-main">Flavivirus 5' UTR</span> Untranslated regions in the genome of viruses in the genus Flavivirus

Flavivirus 5' UTR are untranslated regions in the genome of viruses in the genus Flavivirus.

Flavivirus 3' UTR are untranslated regions in the genome of viruses in the genus Flavivirus.

References

  1. 1ICTV 7th Report van Regenmortel, M.H.V., Fauquet, C.M., Bishop, D.H.L., Carstens, E.B., Estes, M.K., Lemon, S.M., Maniloff, J., Mayo, M.A., McGeoch, D.J., Pringle, C.R. and Wickner, R.B. (2000). Virus taxonomy. Seventh report of the International Committee on Taxonomy of Viruses. Academic Press, San Diego.1162 pp. https://ictv.global/ictv/proposals/ICTV%207th%20Report.pdf
  2. "Yokose virus". www.genome.jp. Archived from the original on 2019-12-13. Retrieved 2019-12-13.
  3. 1 2 Omatsu, Tsutomu; Watanabe, Shumpei; Akashi, Hiroomi; Yoshikawa, Yasuhiro (2007-09-01). "Biological characters of bats in relation to natural reservoir of emerging viruses". Comparative Immunology, Microbiology and Infectious Diseases. Special Issue: Recent research progress on emerging infectious diseases in Asia and Oceania. 30 (5): 357–374. doi:10.1016/j.cimid.2007.05.006. ISSN   0147-9571. PMC   7112585 . PMID   17706776.
  4. 1 2 3 4 5 6 7 Tajima, Shigeru; Takasaki, Tomohiko; Matsuno, Shigeo; Nakayama, Mikio; Kurane, Ichiro (2005-02-05). "Genetic characterization of Yokose virus, a flavivirus isolated from the bat in Japan". Virology. 332 (1): 38–44. doi: 10.1016/j.virol.2004.06.052 . ISSN   0042-6822. PMID   15661139.
  5. 1 2 3 "Flavivirus ~ ViralZone page". viralzone.expasy.org. Archived from the original on 2019-05-03. Retrieved 2019-12-13.
  6. 1 2 3 Apte-Sengupta, Swapna; Sirohi, Devika; Kuhn, Richard J. (2014). "Coupling of Replication and Assembly in Flaviviruses". Current Opinion in Virology. 9: 134–142. doi:10.1016/j.coviro.2014.09.020. ISSN   1879-6257. PMC   4268268 . PMID   25462445.
  7. 1 2 3 Feng, Yun; Ren, Xiaojie; Xu, Ziqian; Fu, Shihong; Li, Xiaolong; Zhang, Hailin; Yang, Weihong; Zhang, Yuzhen; Liang, Guodong (2019-01-11). "Genetic diversity of the Yokose virus, XYBX1332, isolated from bats (Myotis daubentonii) in China". Virology Journal. 16 (1): 8. doi: 10.1186/s12985-018-1107-3 . ISSN   1743-422X. PMC   6330390 . PMID   30634973.
  8. 1 2 3 Watanabe, Shumpei; Omatsu, Tsutomu; Miranda, Mary E. G.; Masangkay, Joseph S.; Ueda, Naoya; Endo, Maiko; Kato, Kentaro; Tohya, Yukinobu; Yoshikawa, Yasuhiro; Akashi, Hiroomi (2010). "Epizootology and experimental infection of Yokose virus in bats". Comparative Immunology, Microbiology and Infectious Diseases. 33 (1): 25–36. doi:10.1016/j.cimid.2008.07.008. ISSN   1878-1667. PMC   7112705 . PMID   18789527.